Ewe colostrum and subsequent lamb suckling behaviour

Behavioural and colostral data were obtained from 70 parous Border Leicester x Merino ewes (and their lambs) that lambed in 0.25 ha paddocks. Data collected included a colostral sample immediately postpartum, lamb weight and temperature, site of parturition and lamb sucking attempts to 48 h post-partum. Colostrum dry matter percentage was 56.5 for ewes with single lambs and 61.5 for ewes with twins (P<0.05). Colostrum colour and consistency score (1-7) of twin-bearing ewes was 5.5 compared with single-bearing ewes of 6.5 (nearer normal milk). Lamb sucking behaviour suggested the more viscous the colostrum, the more often the lamb attempts to suck (P<0.001) and for a longer period at each attempt (P<0.05). This effect diminished over time so that by 24-48 h there was no difference in behaviour expressed as duration x number of sucking bouts, when normal milk would be expected. Twin lambs had significantly more sucking bouts than single lambs up to 4 h post partum. The consequences of these observations would be more serious for twin lamb survival and may explain why some individual twin lambs often die from starvation.